It is known to construct a plastic bag by folding a continuous web of thermoplastic material over on itself, then making an infold at the folded edge, to form a gusset, and then simultaneously cutting and heat sealing the folded web along spaced apart transverse lines. Each individual bag formed in this manner has a "M" shaped cross section at the gusset. Bags constructed in this manner are inherently capable of assuming a substantially hexahedron shape when filled with a proper quantity of a particular type of goods. This type of bag is commonly referred to as a "bread bag" and is used for packaging loaves of bread. The bread loaf is inserted into the bag through an open end that is opposite the gusset. The open end is then tied shut in an appropriate manner.
It is also known to provide bags of this type with an add-on handle at the closed or gusset end of the bag. By way of an example, French Patent Publication 2,053,590, published in 1971, by inventor Christen Huni, discloses an add-on handle which extends transversely across the gusset end of the bag. The opposite ends of the handle include flanges which are heat welded to the opposite sidewalls of the bag substantially where they are joined to the top or gusset of the bag.
It is also known to make a handle bag of this general type in which the handle member is made long enough so that a person's arm can be fit between it and the gusset, enabling the bag to be carried on the arm if a user desires to carry the bag in this manner. Such a bag is disclosed by U.S. Pat. No. 4,573,203, granted Feb. 25, 1986, to Harry R. Peppiatt.
A disadvantage of a bag of this type is that the handle is an add-on handle and a heat seal must be provided between the bag body and the handle through which forces are transmitted during the carrying of the bag and its contents. The attached end portions of the handle side laps the sidewalls of the bag material and the tension forces in the film must "jog" through the heat seal as they are transferred from the sidewalls of the bag to the handle. The tension forces want to pull the bag film and the handle film into a single plane but this is not possible. What happens is that the lower edge portion of the handle, which depends from the seal line, flairs outwardly somewhat from the sidewalls of the bag. Also, the process used for connecting the handle to the sidewalls puckers the connecting edge and in effect pleats the depending edge portion. Another problem is that the exposed lower boundary of the handle is quite often irregular. This irregular boundary, the vertical pleats in the depending edge, and the bending up of the edge from the bag walls combine to produce a relatively unattractive juncture between the handle and the bag body.
A principal object of the present invention is to provide a bag construction characterized by bag sidewalls which continue upwardly over a closed top to form a handle. The handle is a continuation of the sidewall material and as a result the handle connection is in the same plane with the bag sidewalls at the juncture between the sidewalls and the handle. Also, there is no depending edge portion of the handle, resulting in a much neater appearing transition between the bag sidewalls and the handle.
It is known to construct packaged bags which have sidewalls which merge into the handle. However, these bags are open top bags. An example of such a bag is disclosed by U.S. Pat. No. 3,580,486, granted May 25, 1971, to Emanuel Kugler.
It is also known to construct a plastic bag to include both a gusset and opposite side handle portions at its upper end. The bag is end folded an amount to form both a gusset and handle portions which project above the gusset. The folded end portions are heat sealed along parallel lines which are vertically positioned between the center fold of the gusset and fold lines formed at the upper boundary of the bag. A bag of this type is disclosed by Canadian Pat. No. 907,574, granted Aug. 15, 1972 to Herbert F. Gerband. One problem of this type of construction is that it requires the use of more material than is necessary in the construction of the bag. Also, it results in a pair of grip handles on opposite sides of the bag which may not be desirable for some uses. Another object of the present invention is to provide a bag constructed to assume a substantially hexahedron shape when filled which includes a side-to-side continuous handle which is formed from the pieces of material which form the sidewalls of the bag, and which includes a closed top formed from a separate piece of material.